Search results
Results from the WOW.Com Content Network
Composite image showing JPG and PNG image compression. Left side of the image is from a low-quality JPEG image, showing lossy artefacts; the right side is from a PNG image. In information technology , lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data ...
In the most extreme case only the DC-coefficient, that is the coefficient which represents the average color of a block, is retained, and the transform block is only a single color after reconstruction. Because this quantization process is applied individually in each block, neighboring blocks quantize coefficients differently.
Continuously varied JPEG compression (between Q=100 and Q=1) for an abdominal CT scan. JPEG (/ ˈ dʒ eɪ p ɛ ɡ / JAY-peg, short for Joint Photographic Experts Group and sometimes retroactively referred to as JPEG 1) [2] [3] is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography.
Software distributors use executable compression for a variety of reasons, primarily to reduce the secondary storage requirements of their software; as executable compressors are specifically designed to compress executable code, they often achieve better compression ratio than standard data compression facilities such as gzip, zip or bzip2 [citation needed].
Guetzli optimizes the quantization step of encoding to achieve compression efficiency. It constructs custom quantization tables for each file, decides on color subsampling, [4] and quantizes adjacent DCT coefficients to zero, balancing benefits in the run-length encoding of coefficients and preservation of perceived image fidelity.
The .ZIP file format was designed by Phil Katz of PKWARE and Gary Conway of Infinity Design Concepts. The format was created after Systems Enhancement Associates (SEA) filed a lawsuit against PKWARE claiming that the latter's archiving products, named PKARC, were derivatives of SEA's ARC archiving system. [3]
Like any resampling operation, changing image size and bit depth are lossy in all cases of downsampling, such as 30-bit to 24-bit or 24-bit to 8-bit palette-based images.. While increasing bit depth is usually lossless, increasing image size can introduce aliasing or other undesired artifa
1/400 sec (0.0025) F-number: f/9: ISO speed rating: 100: Date and time of data generation: 15:30, 1 July 2017: Lens focal length: 12 mm: User comments: Jared Winkler: Horizontal resolution: 72 dpi: Vertical resolution: 72 dpi: Software used: Adobe Photoshop Lightroom 6.10.1 (Windows) File change date and time: 20:25, 9 July 2017: Exposure ...